Special Charges (Credits) - Components of Special Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating:
CARES Act grant	$ 0	$ (4,021)	$ (3,536)
Severance and benefit costs	0	438	575
Impairment of assets	0	97	318
(Gains) losses on sale of assets and other special charges	140	119	27
Total operating special charges (credits)	140	(3,367)	(2,616)
Nonoperating unrealized (gains) losses on investments, net	(20)	34	194
Nonoperating debt extinguishment and modification fees	7	50	0
Nonoperating special termination benefits and settlement losses	0	31	687
Nonoperating credit loss on BRW Term Loan and related guarantee	0	0	697
Total nonoperating special charges and unrealized (gains) losses on investments, net	(13)	115	1,578
Total operating and nonoperating special charges (credits) and unrealized (gains) losses on investments, net	127	(3,252)	(1,038)
Income tax expense (benefit), net of valuation allowance	(33)	728	404
Total operating and nonoperating special charges (credits) and unrealized (gains) losses on investments, net of income taxes	$ 94	$ (2,524)	$ (634)